Adhesion of polyamide or polyester cords to rubber

ABSTRACT

An aqueous alkaline dispersion of a rubbery graft low gel vinyl pyridine copolymer and a water soluble, heat reactive phenolic resin is useful in forming an adhesive for bonding polyamide or polyester reinforcing elements or cords to rubber compounds or stocks. After dipping the polyamide or polyester cord in the one-step adhesive dip, the coated cord is heated to dry it and heat cure or heat set the adhesive on the cord. Thereafter, the adhesive containing polyamide or polyester cord is combined with, or laminated to (calendered), a curable rubber compound and the resulting assembly is cured to form a composite in which the polyamide or polyester cord is bonded to the rubber by means of said adhesive.

This invention relates to the adhesion of polyamide or polyester cordsto rubber using an adhesive composition of a rubbery graft low gel vinylpyridine copolymer and a phenolic-aldehyde resin.

OBJECTS

An object of the invention is to provide a composite of a polyamide orpolyester reinforcing element adhesively bonded to a rubber compound,e.g., polyamide or polyester tire cords adhesively bonded to rubber toprovide carcass piles and belt piles for making tires. Another object isto provide polyamide or polyester reinforcing elements, e.g., such asthose used in the belt and the carcass plies of tires, with a minoramount of an adhesive so that the adhesive containing elements maysubsequently be bonded to rubber on curing. A further object is toprovide a method for bonding polyamide and/or polyester reinforcingelements, particularly polyamide and polyester textiles, fibers, cords,yarns and so forth, to rubber compounds using a single dip. A stillfurther object is to provide a polyamide or polyester fiber or cordadhesive dip composition. These and other objects and advantages of thepresent invention will become more apparent to those skilled in the artfrom the following detailed description and working examples.

DISCUSSION OF THE PRIOR ART

Copending U.S. patent application Ser. No. 14,659 filed Feb. 23, 1979,abandoned, discloses that an aqueous alkaline dispersion of a rubberyvinyl pyridine copolymer, a rubbery polybutadiene or a rubbery copolymerof at least 80% butadiene and the balance a mono-ethylenicallyunsaturated monomer, and a water soluble, heat reactablephenolic-aldehyde resin, in certain amounts, wherein the rubberypolymers have a reduced amount of gel, is useful in forming an adhesivefor bonding glass fiber reinforcing elements or cords to rubbercompounds or stocks. After dipping the glass fiber cord in the one-stepadhesive dip, the coated cord is heated to dry it and heat cure or heatset the adhesive on the cord. Thereafter, the adhesive containing glassfiber cord is combined with, or laminated (calendered) to, a curablerubber compound and the resulting assembly is cured to form a compositein which the glass fiber cord is bonded to the rubber by means of saidadhesive.

SUMMARY OF THE INVENTION

According to the present invention it has been discovered that acomposition comprising an aqueous alkaline dispersion of a rubbery lowgel vinyl pyridine graft copolymer, and a heat reactable water solublephenolic-aldehyde resin, in certain amounts, is very useful as atreating, dipping or coating material for use in bonding polyamide orpolyester reinforcing elements to rubber compounds. Sufficient alkalinematerial such as aqueous NH₃, KOH or NaOH may be added to the dispersion(or to one or more of the ingredients of the dispersion before mixingthem together) to obtain the desired pH, prevent coagulation of thelatex and to provide for stabilization. This will vary with the pH ofthe resin and the latex, all of which may vary from batch to batch.Since the amount of each compound may vary, the amount of alkalinematerial required can also vary. After drying the adhesive on thepolyamide or polyester reinforcing element to remove water and to heatcure or heat set the adhesive on the element, the adhesive containingelement can then be combined or calendered with a curable rubbercompound and the resulting assembly cured, usually in a mold, to providea laminate exhibiting good adhesive properties.

The use of the low gel rubbery graft vinyl pyridine copolymer enablesthe obtainment of high H-adhesions, in some cases higher thanconventional adhesives using vinyl pyridine copolymers, but using lessbound vinyl pyridine monomer. Forming a core or seed of BD-STYcopolymers and a shell or graft of BD-VP copolymer means that more VP ison the outside of the copolymer rather than inside of it. It isrecognized that a rubbery polymer is a mixture of curled intertwinedrubber chains. Moreover, since most of the styrene is in the core ratherthan in the shell, the Tg of the final polymer is not raisedsubstantially, nor is the stiffness. An all styrene-vinyl pyridinecopolymer shell or styrene-vinyl pyridine-butadiene shell tends to besoluble in the core and to increase stiffness and the Tg of the graftcopolymer.

The present method involves only one dipping step, and the process ormethod can be varied to provide the desired pick-up or solids on thecord by varying the concentration of the dip or the speed of the cordthrough the dip to give the amount needed to develop the requisiteadhesive bond. Thus, while the cord can be run through successive dipsof the same or varying amounts of the above materials to get the desiredbuildup, this is unnecessary as satisfactory results generally can beaccomplished in one dip.

DISCUSSION OF DETAILS AND PREFERRED EMBODIMENTS

The polyamide used as a reinforcing element may be an aromaticpolyamide, an aliphatic polyamide, or a polyamide containing bothaliphatic and aromatic units. These long chain polymeric amides arecapable of being formed into filaments and have recurring amide groupsas an integral part of the main polymer chain. The polyamide element canbe a homopolymer, block or random copolymer, or a mixture of two or moreof such polymers. The polyamide will usually have both crystalline andamorphous regions. Groups other than amide, respectively, may be presentin minor amounts in these polymers, such groups including carbonate,urea, urethane, ether, ketone, imidazole, oxazole, and otheroxygen-containing moieties.

In general, these high molecular weight polyamides are obtained byreacting polyamines, such as the alpha, omega-diamines, like1,6-hexamethylene diamine, 1,5-pentamethylene diamine and1,8-octamethylene diamine, with polycarboxylic acids, such as adipicacid, succinic acid, phthalic acid, chlorophathalic acid and the like.The polyamides may also be prepared by polymerization of aminocarboxylicacids, such as aminocaproic acid. Polyamides from caprolactam andp-aminobenzoic acid also can be used.

The high molecular weight aromatic or substantially aromatic polyamidesmay be obtained by condensation of metaphenylene diamines withisophthalic acid or paraphenylene diamines with terephthalic acids or m,p, or o-benzamides or mixtures of the above isomeric amines withisomeric acids. It is also possible to make polyamides using the abovementioned isomers with substituents on the phenyl groups, halogen(--Cl), alkyl (CH₃ --), etc., or to use biphenyl acids with diamines oraromatic diamines and/or diacids in which the aromatic nuclei are spacedby:

    --O--, --SO--, --CH.sub.2 --, --CO--

and so forth. Instead of phenylene groups, the polymers can partly ortotally contain heterocyclic rings.

Examples of such materials are polyhexamethylene adipamide, copolymersof metaphenylene diamine and terephthalic or isophthalic acid or acidchloride, poly[bis-(4-amino-cyclohexyl)methanedodecamide], polypara-phenylene terephthalamide from phenylenediamine and terephthaloylchloride, poly (hexamethylene terephthalamide), poly-m, or p-benzamideand the like. Examples of commercially available aliphatic polyamidesare nylon 6 and nylon 66. Example of an aromatic polyamide is "Kevlar"(duPont). See U.S. Pat. Nos. 3,872,937; 3,888,805; and "Rubber &Plastics News," Mar. 19, 1979, pages 44-49.

The polyester reinforcing elements of the present invention are linearhigh molecular polyesters usually made by the condensation ofα,ω-glycols and dicarboxylic acids. These polyester fibers and the likemay be oriented and can have number average molecular weights up toabout 60,000 and melting points up to about 300° C. Preferably, thesepolyesters exhibit substantial crystallinity, up to as much as about50%, usually 38-45%, high strength and high tenacity. Also, preferred,are the polyesters in which the fiber is composed of at least 80% byweight of an ester of a dihydric alcohol and terephthalic acid such aspoly(ethylene terephthalate). Examples of such polyesters are the highmolecular weight polymers obtained from polyethylene glycols and thearomatic dicarboxylic acids, e.g., the high molecular weightcondensation product obtained from ethylene glycol and terephthalic acidknown as polyethylene terephthalate. Other polyesters which may be usedare poly(ethylene oxybenzoate); polypivalalactone; terpolymers fromdimethyl phthalate, dimethyl isophthalate and ethylene glycol;polyesters having at least two different repeating units from ethyleneterephthalate, p-trimethylene oxybenzoate, and ethylene-1,4-diphenoxybutane-4,4'-dicarboxylate; poly (ethylene terephthalate-isophthalate);poly (1,4-cyclohexylenedimethylene terephthalate); and the like andmixtures thereof. Suitable polyester reinforcing elements arecommercially available under the trademarks "Dacron" (duPont), "Encron"(American Enka Corporation) and "Vycron" (Beaunit Corporation). Thesehigh molecular weight linear polyesters are well known and can be madeby methods known to the art. For example, the preparation of polyestersis shown by U.S. Pat. Nos. 2,465,319; 2,965,613 and 2,901,466. See,also, U.S. Pat. No. 3,861,980.

The polyamide or polyester reinforcing elements may be in the form offibers, continuous filaments, staple, tow, yarns, cord, fabric and soforth. While mixtures of polyamide and polyester fibers etc. may beused, it is preferred to use one type of polymer. These polyamide orpolyester cords may contain finishes or lubricants or be preactivated asthey are made and sold, e.g., with urethane or epoxy groups forpolyester.

The water soluble thermosetting (heat reactable) phenolic-aldehyde resinis made by reacting an aldehyde with a phenolic compound. An excess(over stoichiometry) of the aldehyde is reacted with the phenoliccompound. The preferred aldehyde to use is formaldehyde, butacetaldehyde and furfural, also, may be used. In place of formaldehydeone may use paraform, the dry powder form of formaldehyde. Also, it ispreferred to start with formalin, usually a 37% solution of formaldehydein water, which is easier to use. Mixtures of aldehydes can be used. Thephenolic compound can be phenol itself, resorcinol, the cresols, thexylenols, p-tert butylphenol or p-phenyl phenol or mixture thereof.Preferably, the reactants are formaldehyde and resorcinol which arereacted in water usually in the presence of an alkaline catalyst or analkaline material is added before use. Information on the preparation ofthe water soluble thermosetting phenolic-aldehyde resins will be foundin "Encyclopedia of Chemical Technology," Kirk-Othmer, Volumn 15, SecondEdition, 1968, Interscience Publishers Division of John Wiley & Sons,Inc., New York, pages 176 to 208; "Technology of Adhesives," Delmonte,Reinhold Publishing Corp., New York, N.Y., 1947, pages 22 to 52;"Formaldehyde," Walker, A.C.S. Monograph Series, Reinhold PublishingCorp., New York, N.Y., Third Edition, 1964, pages 304 to 344 and "TheChemistry of Phenolic Resins," Martin, John Wiley & Sons, Inc., NewYork, 1956.

If desired, with more emphasis with respect to polyester cords, theremay additionally be added to the aqueous phenolic-aldehyde resin latexdip a heat reactable 2,6-bis(2,4-dihydroxy phenylmethyl)-4-chlorophenolcomposition usually as a 20% solids in aqueous alkaline (ammonia)solution. On a dry weight basis the chlorophenolic composition may beused in an amount by weight about substantially equal to the amount ofthe RF resin used. The chlorophenolic is a known compound ("Pexul" orH-7, I.C.I. America Inc.). See U.S. Pat. Nos. 3,660,202 and 3,861,980.

The rubbery graft copolymer or core/shell copolymer of butadiene-1,3,styrene and 2-vinyl pyridine is made by first forming a seed latex of acopolymer of butadiene-1,3, and styrene having parts by weight ratio offrom about 40 to 60 of butadiene-1,3 to from about 60 to 40 of styreneusing the method of U.S. Pat. No. 4,145,494, the disclosure of which isincorporated herein and made a part hereof by reference to the same. Thecopolymerization is carried to at least 85% conversion to form a seed(core) or back bone copolymer of butadiene-1,3 and styrene. According toU.S. Pat. No. 4,145,494 aqueous free radical emulsion polymerization ofdienes and vinyl monomers is carried out using a mercaptan modifier orchain transfer agent wherein at at least 75% conversion 11/2 times theamount of modifier previously used is charged to the polymerizationsystem and wherein the total modifier used is about 0.75 to 2.5 parts byweight for 100 parts by weight of monomer(s).

After the seed latex has been formed there is then charged to thereactor a mixture of butadiene-1,3 and 2-vinyl pyridine to form theshell or graft copolymer on the core. Other vinyl pyridines may be usedsuch as 3-vinyl pyridine, 4-vinyl pyridine, 2-methyl-5-vinyl pyridineand 5-ethyl-2-vinyl pyridine. The amount of butadiene-1,3 and vinylpyridine charged is a minor amount as compared to the amount charged tomake the core or seed latex. However, the total amount charged should besufficient to make in the final rubbery graft copolymer (core plusshell) of from about 47 to 69% by weight of butadiene, from 23 to 52% byweight of styrene and from 1 to 8% by weight of 2-vinyl pyridine. Thepolymerization is then completed following the procedure of U.S. Pat.No. 4,145,494 to the desired conversion followed by steam stripping,preferred, or N₂ degassing. Sufficient emulsifier or stabilizer iscarefully programmed during the shell formation on the core into thepolymerization system to be absorbed on the copolymer particles so thatthe seed will grow and a graft or shell will form. Excess emulsifiershould not be used to avoid formation of new micelles or particles. See"Encylopedia of Polymer Science And Technology," Vol. 5, 1966,Interscience Publishers a division of John Wiley & Sons, Inc., New York.Final conversion (total core plus shell) may be above about 90%, thedegree of final conversion depending generally on the economics involvedand the amount of gel desired. It, thus, is seen that the core isgenerally substantially entirely a BD-STY copolymer; however, ifpolymerization is not complete, some STY may be copolymerized with theBD and VP of the shell. The gel content of the inner core or seed of thegraft copolymer should be from about 0 to below 40%. The gel content ofits outer graft or shell of the graft copolymer should preferably beabout 0 to below 40% but may go up to below 70% (about 0 to <70%) ifeconomics dictate high conversion and the H-adhesion is not adverselyaffected too much by such high conversions.

The latex may be post stabilized, care being observed to avoid materialswhich do not improve resistance to coagulation (on stirring) and/orwhich reduce H-adhesion adversely. Sodium decyl sulfate at 0.5 part didnot affect polyester adhesion, improved nylon adhesion and improvedmechanical stability of the latex. Normal additives such as urea, sodiumsulfide, formaldehyde, and hydroquinone do not apparently affectH-adhesion. Potassium fatty acid soap causes a reduction in adhesion.Some other surfactants show a drop in H-adhesion.

The gel content of the shell, core or both of the rubbery vinyl pyridinegraft copolymer may be determined by taking a sample of the particularlatex involved, coagulating the rubber and separating the rubber fromthe water, milling the rubber obtained, dissolving the rubber in tolueneand filtering the mixture to determine the gel content. See Whitby etal, "Synthetic Rubber," John Wiley & Sons, Inc., New York, 1954. Thetechnique of polymerizing or copolymerizing one or more monomers in thepresence of a polymer or a substrate, "grafting technique," is known andis frequently called graft polymerization or graft copolymerization. Inthis connection, please see "Copolymerization," High Polymers, Vol.XVIII, Ham, Pages 323-324, 335-420 and 573, Interscience Publishers adivision of John Wiley & Sons, New York, 1964; "Block and GraftPolymers," Burlant and Hoffman, Reinhold Publishing Corporation, NewYork, 1960; "Block and Graft Copolymers," Ceresa, Butterworth & Co.(Publishers) Ltd., London, 1962; and "Graft Copolymers," PolymerReviews, Vol. 16, Battaerd and Tregear, Interscience Publishers, adivision of John Wiley & Sons, New York, 1967. The graft copolymer shellmay contain all graft copolymer but also may be a mixture ofhomopolymers, copolymers as well as the graft itself. Thus, if theconversion of the core is not complete, then when the BD and VP arecharged, the shell may contain some STY homopolymer, BD homopolymer,BD-STY, BD-VP and BD-VP-STY copolymers and so forth as well as thegraft. However, what is important is that the VP (vinyl pyridine)moieties are on the outside of the copolymer where the adhesive effectis obtained.

The water soluble thermosetting RF resin and the rubbery copolymer arepresent together in the aqueous adhesive dispersion in an amount of fromabout 10 to 30% by weight solids (dry basis). The ratio of the RF resinto the rubbery vinyl pyridine graft copolymer on a dry weight basisgenerally is from about 10:100 to 40:100 parts be weight, preferablyfrom about 12:100 to 30:100 parts by weight.

Up to about 50 parts by weight of the rubbery graft vinyl pyridinecopolymer latex may be replaced with alkaline latex of a rubberycopolymer of about 40-50, preferably about 44-48, parts by weight ofstyrene and the balance butadiene-1,3. However, some loss in H-adhesionmay be observed.

The pH of the dip should be on the alkaline side and the pH of anysurfactants and stabilizers, including freeze-thaw stabilizers and otheradditives, should be on the alkaline side or compatible or be neutral toavoid improper coagulation of the latex(es).

Water is used in an amount sufficient to provide for the desireddispersion of the rubber or latex particles, and for the solution of thephenolic resin and any other additives, to obtain the desiredviscosities, and for the proper solids content to get the necessarypickup of solids on and penetration between the fibers of the cord. Theamount of water in the cord dip generally may vary as desired. However,too much water may require redipping or use of excess heat to evaporatethe water on drying. Too little water may cause uneven coating or tooslow coating speeds.

To apply the latex adhesive to the polyamide or polyester cords in areliable manner, the cords are fed through the adhesive dip bath whilebeing maintained under a small predetermined tension and into a dryingoven where they are dried under a small predetermined tension. Slightstretching may be used where desired. As the cords leave the oven theyenter a cooling zone where they are air cooled before the tension isreleased. In each case the adhesive-coated cords leaving the dip aredried in the oven at from about 300 to 500° F. (148.9° to 260° C.) forfrom about 150 to 30 seconds.

The time the cord remains in the adhesive is about a few seconds or moreor at least for a period of time sufficient to allow wetting of the cordand some impregnation of the surface fibers of the cord. The dipping ofthe cords and the drying or curing of the adhesive treated polyamide orpolyester cords may be accomplished in one or more dip tanks and in oneor more ovens at different times and temperatures.

The single-cord H-pull, H-adhesion, test is employed to determine thestatic adhesion of the dried (heat set or cured) adhesive coatedpolyamide or polyester cords to rubber. In each case the rubber testspecimens are made from a vulcanizable rubber composition comprisingrubber, reinforcing carbon black and the customary compounding andcuring ingredients. In every case the cords to be tested are placed inparallel positions in a multiple-strand mold of the type described inthe single-cord H-pull adhesion test ASTM designated D 2138-67, the moldis filled with the unvulcanized rubber composition, the cords beingmaintained under a tension of 50 grams each, and the rubber is cured for20 minutes at about 305° F. (151.7° C.) to the elastic state. Eachrubber test specimen is 1/4 inch thick and has a 3/8 inch cordembedment. After the rubber has been cured, the hot cured rubber pieceis removed from the mold, cooled and H-test specimens are cut from saidpiece, each specimen consisting of a single cord encased in rubber andhaving each end embedded in the center of a rubber tab or embedmenthaving a length of around 1 inch or so. The specimens are then aged atleast 16 hours at room temperature (about 25° C.).

The force required to separate the cord from the rubber is thendetermined at room temperature or 250° F. (121.1° C.) using an INSTRONtester provided with specimen grips. The maximum force in poundsrequired to separate the cord from the rubber is the H-adhesion value.All the data submitted in the working examples which follow are basedupon identical test conditions, and all of the test specimens wereprepared and tested in the same way generally in accordance with ASTMDesignation: D 2138-67.

Polyamide or polyester cords or fabric coated with the adhesive of thepresent invention using the one-step or single dip of this invention canhave from about 3 to 15%, preferably from about 3 to 7%, by weight (dry)solids of the adhesive dip on the cord based on the weight of the cordand can be used in the manufacture of carcasses, belts, flippers andchafers of radial, bias, or belted-bias passenger tires, truck tires,motorcycle tires, off-the-road tires and airplane tires, and, also, inmaking transmission belts, V-belts, conveyor belts, hose, gaskets,tarpaulins and the like.

While the adhesive containing polyamide or polyester reinforcingelements can be adhered to a vulcanizable blend of natural rubber,rubbery cis-polybutadiene and rubbery butadiene-styrene copolymer or ablend of natural and rubbery butadiene-styrene copolymer by curing thesame in combination together, it is apparent that the heat curedadhesive containing reinforcing elements can be adhered to othervulcanizable rubbery materials, by curing or vulcanizing the same incombination with the rubber, such as one or more of the foregoingrubbers as well as nitrile rubbers, chloroprene rubbers, polyisoprenes,polybutadienes, vinyl pyridine rubbers, acrylic rubbers,isoprene-acrylonitrile rubbers and the like and mixtures of the same.These rubbers can be mixed with the usual compounding ingredientsincluding sulfur, stearic acid, zinc oxide, magnesium oxide, silica,carbon black, accelerators, antioxidants, antidegradants and othercuratives, rubber compounding ingredients and the like well known tothose skilled in the art for the particular rubbers being employed.Also, the adhesive dip of the present invention may also be used toadhere other cords, yarns and the like to rubber compounds.

The following examples will serve to illustrate the present inventionwith more particularity to those skilled in the art. In the examples theparts are parts by weight unless otherwise indicated.

EXAMPLE I

A polyester cord dip was made as follows. First, a resin composition wasmade:

    ______________________________________                                                            Parts  Parts                                              Ingredient          Dry    Wet                                                ______________________________________                                        Soft Water          --     333.4                                              Sodium Hydroxide    1.3    1.3                                                Resorcinol          16.6   16.6                                               Formaldehyde (37%)  5.4    14.7                                               Total               23.3   366.0                                              ______________________________________                                    

The resin composition was then mixed with the latex to make the dip asfollows:

    ______________________________________                                                             Parts  Parts                                             Ingredient           Dry    Wet                                               ______________________________________                                        Resin Comp.           23.3  366.0                                             Latex (about 41% TSC)                                                                              100.0  244.0                                                                  123.3  610.0                                             ______________________________________                                    

Total solids content of adhesive dip of about 20% (for purposes ofcalculating TSC use 4 parts of formaldehyde). pH of 9.5.

The dip was then used to treat polyester cords which were dried or heatset, laminated with a rubber compound, cured and given an H-adhesiontest as described supra.

A polyamide cord dip was made as follows (for Exampe II, below). First,a resin composition was made:

    ______________________________________                                        Composition                                                                                       Parts  Parts                                              Ingredient          Dry    Wet                                                ______________________________________                                        Soft Water          --     238.5                                              Sodium Hydroxide    0.3    0.3                                                Resorcinol          11.0   11.0                                               Formaldehyde (37%)  6.0    16.2                                               Total               17.3   266.0                                              ______________________________________                                    

The resin composition was then mixed with the latex to make the dip asfollows:

    ______________________________________                                                             Parts  Parts                                             Ingredient           Dry    Wet                                               ______________________________________                                        Resin Comp.           17.3  266.0                                             Latex (about 41% TSC)                                                                              100.0  244.0                                             Soft Water           --      60.0                                             Total                117.3  570.0                                             ______________________________________                                    

Total solids content of adhesive dip of about 20% (for purposes ofcalculating TSC use 3 parts of formaldehyde). pH of 9.

The dip was then used to treat polyamide cords which were dried or heatset, laminated with a rubber compound or stock, cured and tested forH-adhesion (See Example II) as described below.

The rubbery graft vinyl pyridiene copolymer latex used was prepared asdescribed above and according to the teachings of U.S. Pat. No.4,145,494. Except where noted, the core or seed was carried to aconversion of at least 85%. The extent of gel content is noted as H (70%and over), M (40 to below 70%) and L (0 to less than 40%). Theconstitution of latices used and the H-adhesion tests results are shownin the table below:

                                      TABLE I                                     __________________________________________________________________________              Total                                                                   % Gel %                  H-adhesion (lbs) to                                  of    Conv.                                                                             Core   Shell   Polyester (A) Cord                                   Graft of  (Charge to                                                                           (Charge to                                                                            using rubber                                     Latex                                                                             Copolymer                                                                           Graft                                                                             reactor)                                                                             reactor)                                                                              stock P                                          No. Core/Shell                                                                          Copol.                                                                            BD/S. parts                                                                          BD/VP, parts                                                                          Cold Hot                                         __________________________________________________________________________    1   H*/L  96  73.5/1.5                                                                             20/5    29.4 13.8                                        2   L/L   92  73.5/1.5                                                                             20/5    41.0 17.0                                        3   H*/L  88  60/15  20/5    44.5 23.8                                        4   L/L   88  60/15  20/5    45.8 19.5                                        5   H*/L  91  18.7/56.3                                                                            20/5    45.2 22.3                                        6   L/L   91  18.7/56.3                                                                            20/5    48.7 23.1                                        7   L/L   91  37.5/37.5                                                                            20/5    47.5 33.6                                        8   L/L   95.9                                                                              37.5/37.5                                                                            20/5    49.4 34.9                                        9   L/M   96.6                                                                              37.5/37.5                                                                            20/5    44.8 29.3                                        10  L/H   98.7                                                                              37.5/37.5                                                                            20/5    42.8 26.5                                        11  L/L   94  37.5/37.5                                                                            22.5/2.5                                                                              46.1 31.9                                        12  L/L   92  37.5/37.5                                                                            17.5/7.5                                                                              44.5 29.7                                        13  L/L   93  37.5/37.5                                                                            24/1    41.5 --                                          14  L/L   96  37.5/37.5                                                                            25/0    37.3 --                                          15  L/L   91  45/45   9/1    43.9 --                                          16  L/L   92  45/45  10/0    37.7 --                                          17  L/L   92  32.5/32.5                                                                            35/0    37.1 --                                          18  Control                                                                             92.sup.1                                                                          --     --      43.6 30.0                                        19  Control                                                                             99+.sup.1                                                                         --     --      41.5 26.7                                        20  L/L   96  37.5/37.5                                                                            21/4    56.4.sup.2                                                                         --                                          21  L/L   93  37.5/37.5                                                                            20/5    55.2.sup.2                                                                         --                                          22  L/L   93.7                                                                              37.5/37.5                                                                            22/3    54.5.sup.2                                                                         --                                          23  L/M   97.5                                                                              37.5/37.5                                                                            21/4    48.8.sup.2                                                                         --                                          24  L/L   94.7                                                                              37.5/37.5                                                                            21/4    52.8.sup.2                                                                         --                                          __________________________________________________________________________     *Carried to almost 99% conversion using little mercaptan modifier.            .sup.1 Latex of 7015-15 butadienestyrene-vinyl pyridine copolymer prepare     by aqueous free radical emulsion copolymerization in conventional way wit     about 0.6 modifier per/100 total monomers, about 99+% conversion, about       65+% gel, no attempt to make graft copolymer, 41% solids, pH of 10.7,         Mooney viscosity ML4 at 212° F. (100° C.) of about 40.          .sup.2 Rubber Stock Q.                                                   

EXAMPLE II

Additional dips were prepared according to the method of Example I,above, and tested on various cords for H-adhesion. The results obtainedare shown in Table II, below:

                                      Table II                                    __________________________________________________________________________    Latex or                                                                      Latex Blends                                                                           H-adhesion (lbs)                                                     __________________________________________________________________________                                        Polyester C                                        Polyester A                                                                            Polyester B                                                                            Nylon    Rubber Stock Q                                     Rubber Stock Q                                                                         Rubber Stock Q                                                                         Rubber Stock Q                                                                         uz,37/46 H-7(3)                           Latices  Hot  Cold                                                                              Hot  Cold                                                                              Hot  Cold                                                                              Hot  Cold                                 __________________________________________________________________________    Run 20   33.9 54.6                                                                              34.2 50.4                                                                              35.3 52.5                                                                              36.4 61.0                                 Control (1)                                                                            31.2 46.7                                                                              31.2 44.8                                                                              25.4 50.3                                                                              35.7 58.8                                 __________________________________________________________________________                                        Polyester C                                        Polyester A                                                                            Polyester B                                                                            Nylon    Rubber Stock P                                     Rubber Stock P                                                                         Rubber Stock P                                                                         Rubber Stock P                                                                         H-7(3)                                             Cold     Cold     Cold     Cold                                      __________________________________________________________________________    Run 20   40.8     44.7     49.1     42.6                                      Control (1)                                                                            37.8     38.8     52.3     41.2                                      __________________________________________________________________________                                        Polyester C                                        Polyester A                                                                            Polyester B                                                                            Nylon    Rubber Stock Q                                     Rubber Stock Q                                                                         Rubber Stock Q                                                                         Rubber Stock Q                                                                         H-7(3)                                    50/50 Blends                                                                           Hot  Cold                                                                              Hot  Cold                                                                              Hot  Cold                                                                              Hot  Cold                                 __________________________________________________________________________    Run 20/SBR                                                                             30.2 48.4                                                                              29.5 42.2                                                                              33.7 52.0                                                                              29.8 44.4                                 Control(1)/SBR                                                                         29.2 45.2                                                                              25.8 39.7                                                                              31.7 49.8                                                                              28.7 51.3                                 __________________________________________________________________________                                        Polyester C                                        Polyester A                                                                            Polyester B                                                                            Nylon    Rubber Stock P                                     Rubber Stock P                                                                         Rubber Stock P                                                                         Rubber Stock P                                                                         H-7(3) - Cold Cold Cold Cold              __________________________________________________________________________    Run 20/SBR                                                                             32.9     36.5     40.0     31.8                                      Control(1)/SBR                                                                         29.7     36.3     42.0     30.5                                      __________________________________________________________________________                                        Polyester C                                        Polyester A                                                                            Polyester B                                                                            Nylon    Rubber Stock Q                                     Rubber Stock Q                                                                         Rubber Stock Q                                                                         Rubber Stock Q                                                                         H-7(3)                                    80/20 Blends                                                                           Hot  Cold                                                                              Hot  Cold                                                                              Hot  Cold                                                                              Hot  Cold                                 __________________________________________________________________________    Run 20/SBR                                                                             34.8 50.8                                                                              31.2 49.7                                                                              36.0 52.4                                                                              33.1 53.8                                 Control(1)/SBR                                                                         32.4 48.1                                                                              28.5 49.1                                                                              31.2 45.3                                                                              32.4 52.9                                 __________________________________________________________________________                                        Polyester C                                        Polyester A                                                                            Polyester B                                                                            Nylon    Rubber Stock P                                     Rubber Stock P                                                                         Rubber Stock P                                                                         Rubber Stock P                                                                         H-7(3)                                             Cold     Cold     Cold     Cold                                      __________________________________________________________________________    Run 20/SBR                                                                             35.7     39.7     43.0     35.7                                      Control (1)/SBR                                                                        32.4     42.9     48.3     32.4                                      __________________________________________________________________________     (3)Polyester cord dip contained additionally 125.0 parts wet (on 610 part     wet of RFL) H7 solution (20% H7 in ammoniacal aqueous solution).         

Notes for above Examples:

Polyester A--Celanese T-811, preactivated.

Polyester B--Celanese T-911, preactivated.

Polyester C--duPont "Dacron."

SBR--Latex of aqueous free radical emulsion polymerized rubberycopolymer of about 44-48% by weight of styrene and the balancebutadiene-1,3, about 41-43% solids, pH of 10.5-11.5, Mooney viscosity of60 to 90 ML-4 at 212° F. (100° C.), prepared in usual way with lowmodifier and no attempt to make a seed nor a graft copolymer.

H-7--2,6-bis (2,4-dihydroxyphenylmethyl)-4-chlorophenol composition.

BD--Butadiene-1,3.

S--Styrene.

VP--2-vinyl pyridine.

P is the rubber compound or stock used for a series of H-adhesion tests:

    ______________________________________                                        Component             Parts by Weight                                         ______________________________________                                        Natural Rubber        50.                                                     Peptizer              .15                                                     Butadiene-Styrene rubber, SBR-                                                                      50.                                                     1502                                                                          High abrasion furnace carbon                                                                        35.                                                     black                                                                         ZnO                   3.                                                      Stearic Acid          1.                                                      Processing resin      2.                                                      Styrenated phenol     1.                                                      Naphthenic type oil, non-                                                                           7.                                                      staining                                                                      Diphenyl guanidine    .15                                                     "Nobs" #1, 90% N-oxydiethylene-                                                                     0.9                                                     2-benzothiazyl-sulfenamide and                                                10% benzothiazyl disulfide,                                                   American Cyanamid Co.                                                         Sulfur                2.60                                                    ______________________________________                                    

Q is the rubber compound or stock used for another series of H-adhesiontests:

    ______________________________________                                        Component             Parts by Weight                                         ______________________________________                                        Natural Rubber        46.50                                                   Polybutadiene rubber, cis type,                                                                     15.00                                                   solution polymerized, The                                                     General Tire & Rubber Co.                                                     SBR 1778              52.90                                                   (Blend 38.50 cold SBR                                                         Rubber and 14.40 Naphthenic                                                   Oil)                                                                          Fine Extrusion Furnace Carbon                                                                       66.00                                                   Black                                                                         Tackifying resin      2.50                                                    Naphthenic Oil        12.00                                                   Zinc Oxide            3.80                                                    Stearic Acid          1.50                                                    Styrenated Phenol     1.20                                                    "Altax," benzothiazyl disulfide,                                                                    1.10                                                    R. T. Vanderbilt Co.                                                          "Thionex," tetramethyl thiuram                                                                      .10                                                     monosulfide, duPont                                                           "Crystex"(2.40 insoluble sulfur                                                                     3.00                                                    and .60 petroleum oil), Stauffer                                              Chemical                                                                      ______________________________________                                    

I claim:
 1. A composition of matter comprising an aqueous alkalinedispersion of about 10 to 30% by weight solids comprising on a dryweight basis 100 parts by weight of a rubbery graft low gel vinylpyridine copolymer consisting essentially of(a) a core of a copolymer ofbutadiene-1,3 and styrene in the parts by weight ratio of butadiene-1,3to styrene of about 40:60 to 60:40 and having a gel content of fromabout 0 to below 40% and (b) a shell of a copolymer of butadiene-1,3 anda vinyl pyridine and having a gel content of from about 0 to below 70%and (c) where in said graft copolymer the total amount of said monomersis from about 47 to 69% by weight of butadiene-1,3, from 23 to 52% byweight of styrene and from 1 to 8% by weight of the vinyl pyridine and awater-soluble thermosetting phenolic-aldehyde resin in an amount of fromabout 10 to 40 parts by weight.
 2. A composition of matter according toclaim 1 wherein said shell contains a gel content of from about 0 tobelow 40%, where said vinyl pyridine is 2-vinyl pyridine and where saidresin is used in an amount of from about 12 to 30 parts by weight and isa resorcinol-formaldehyde resin.
 3. A composition of another accordingto claim 1 where said solids contain additionally, in an amount byweight substantially equal to the amount of said resin,2,6-bis(2,4-dihydroxyphenylmethyl)-4-chlorophenol composition and wheresaid vinyl pyridine is 2-vinyl pyridine.
 4. A composition of matteraccording to claim 1 in which up to about 50 parts by weight of saidgraft copolymer has been replaced with a rubbery copolymer of about 40to 50 parts by weight of styrene and the balance butadiene-1,3 and wheresaid vinyl pyridine is 2-vinyl pyridine.